1. Field of the Invention
The present invention relates to an organic thin-film transistor and a method for manufacturing the same.
2. Description of the Related Art
Most of display devices such as a liquid crystal display, an organic EL display, and an electrophoretic display include a thin-film transistor (hereinafter, also referred to as a “TFT”) as a display switching device. A TFT includes a gate electrode, a gate insulating layer, a source electrode, and a drain electrode, and the source electrode and the drain electrode are connected to each other through a semiconductor layer.
As materials forming the semiconductor layer of the TFT, inorganic materials such as silicon have been the mainstream.
However, in recent years, organic materials, which can be efficiently used for film formation at a temperature lower than those of inorganic materials, for example, near room temperature at a high speed and at low cost according to a coating method such as a printing method, have been attracting attention and studied.
As the organic materials, an organic semiconductor such as an organic polymer is known.
Further, a combination of such an organic semiconductor and a polymer other than the organic semiconductor has been reported (JP2004-525501A).
Moreover, in an organic thin-film transistor (also referred to as an OTFT), JP2009-177136A describes a method of forming a semiconductor layer having a three-layer structure by phase-separating an organic material that contains TIPS pentacene and poly(α-methylstyrene) or polystyrene.